The “UN” does not make trademark decisions. WIPO is merely an administrative vehicle to facilitate the Paris Convention of 1883 (way before the UN, the Soviet Union or the EU ever blighted earth).
https://en.wikipedia.org/wiki/Paris_Convention_for_the_Protection_of_Industrial_Property
The actual decisions whether to grant or deny protection for a particular trademark (or patent, or design) are made in the member countries.
This is a good thing for all concerned parties.
As long as the UN’s WIPO was allowed to take over this convention, then that is not a good thing, because they will subvert it. The origin is less important than the destination, once the UN was allowed to get its hooks into it (which it did in 1967).